From mboxrd@z Thu Jan  1 00:00:00 1970
From: freeman.zhang1992@gmail.com (freeman)
Date: Thu, 13 Feb 2014 21:28:16 +0800
Subject: [Help] How to Replace File Operations in File System?
In-Reply-To: <CADDndfOGqjxcEtAk+N3W0E41honjBVUknYwPxi7Sd78tw2iB_w@mail.gmail.com>
References: <52FC29B3.10201@gmail.com> <52FC69C7.7010705@gmail.com>
	<CADDndfOGqjxcEtAk+N3W0E41honjBVUknYwPxi7Sd78tw2iB_w@mail.gmail.com>
Message-ID: <52FCC870.3010303@gmail.com>
To: kernelnewbies@lists.kernelnewbies.org
List-Id: kernelnewbies.lists.kernelnewbies.org

Hi Rishi,

Thanks for your reply!

I'm sorry that the description of the problem was not clear.

I am writing a module(not a filesystem) to replace some operation
pointers of Ext4.
Just now, I try to print the dentry->name as you said. It seems
that I'm modifying the right files.

I'm wonderring if my idea is bad:
I changed operations of a file both in ->create and ->lookup in
inode operations of direcotry. And test the module like this:

echo hello > hello      (for dir_inode->create and f->write)
cat hello               (for f->read)


Will the file operations be changed back?
Or what I modified is some copies of real objects because of the
complex caching mechanism?

Regards

Freeman Zhang